Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces

Spin-orbit coupling (SOC) describes the relativistic interaction between the spin and momentum degrees of freedom of electrons, and is central to the rich phenomena observed in condensed matter systems. In recent years, new phases of matter have emerged from the interplay between SOC and low dimensionality, such as chiral spin textures and spin-polarized surface and interface states. These low-dimensional SOC-based realizations are typically robust and can be exploited at room temperature. Here we discuss SOC as a means of producing such fundamentally new physical phenomena in thin films and heterostructures. We put into context the technological promise of these material classes for developing spin-based device applications at room temperature

Antiferromagnetic spintronics

Antiferromagnetic materials are magnetic inside, however, the direction of their ordered microscopic moments alternates between individual atomic sites. The resulting zero net magnetic moment makes magnetism in antiferromagnets invisible on the outside. It also implies that if information was stored in antiferromagnetic moments it would be insensitive to disturbing external magnetic fields, and the antiferromagnetic element would not affect magnetically its neighbors no matter how densely the elements were arranged in a device. The intrinsic high frequencies of antiferromagnetic dynamics represent another property that makes antiferromagnets distinct from ferromagnets. The outstanding question is how to efficiently manipulate and detect the magnetic state of an antiferromagnet. In this article we give an overview of recent works addressing this question. We also review studies looking at merits of antiferromagnetic spintronics from a more general perspective of spin-ransport, magnetization dynamics, and materials research, and give a brief outlook of future research and applications of antiferromagnetic spintronics.Comment: 13 pages, 7 figure

Spin transport and spin torque in antiferromagnetic devices

Ferromagnets are key materials for sensing and memory applications. In contrast, antiferromagnets which represent the more common form of magnetically ordered materials, have found less practical application beyond their use for establishing reference magnetic orientations via exchange bias. This might change in the future due to the recent progress in materials research and discoveries of antiferromagnetic spintronic phenomena suitable for device applications. Experimental demonstration of the electrical switching and detection of the Néel order open a route towards memory devices based on antiferromagnets. Apart from the radiation and magnetic-field hardness, memory cells fabricated from antiferromagnets can be inherently multilevel, which could be used for neuromorphic computing. Switching speeds attainable in antiferromagnets far exceed those of ferromagnetic and semiconductor memory technologies. Here we review the recent progress in electronic spin-transport and spin-torque phenomena in antiferromagnets that are dominantly of the relativistic quantum mechanical origin. We discuss their utility in pure antiferromagnetic or hybrid ferromagnetic/antiferromagnetic memory devices

Magnon-assisted tunnelling in van der Waals heterostructures based on CrBr3

Van der Waals heterostructures, which are composed of layered two-dimensional materials, offer a platform to investigate a diverse range of physical phenomena and could be of use in a variety of applications. Heterostructures containing two-dimensional ferromagnets, such as chromium triiodide (CrI3), have recently been reported, which could allow two-dimensional spintronic devices to be developed. Here we study tunnelling through thin ferromagnetic chromium tribromide (CrBr3) barriers that are sandwiched between graphene electrodes. In devices with non-magnetic barriers, conservation of momentum can be relaxed by phonon-assisted tunnelling or by tunnelling through localized states. In contrast, in the devices with ferromagnetic barriers, the major tunnelling mechanisms are the emission of magnons at low temperatures and the scattering of electrons on localized magnetic excitations at temperatures above the Curie temperature. Magnetoresistance in the graphene electrodes further suggests induced spin–orbit coupling and proximity exchange via the ferromagnetic barrier. Tunnelling with magnon emission offers the possibility of spin injection

Registros sobre dor pós-operatória em crianças: uma análise retrospectiva de hospitais de Londrina, PR, Brasil Registros sobre el dolor post operatorio en niños: un análisis retrospectivo en hospitales de Londrina, PR, Brasil Notes of post-operative pain in children: a retrospective analyses of hospitals from Londrina, PR, Brazil

Toda cirurgia implica em lesão de tecidos, manipulação de estruturas e órgãos, sendo a dor uma conseqüência desse processo, que pode ser minimizada. Este estudo tem como objetivo caracterizar, retrospectivamente, o processo de manejo da dor pós-operatória a partir dos registros contidos em 300 prontuários de 280 crianças de 0 a 14 anos submetidas à cirurgia no ano de 2004 em três hospitais de Londrina, PR. O estudo indicou a existência de poucos registros sobre dor pós-operatória realizados por enfermeiras, sendo a maioria realizada por auxiliares ou técnicos de enfermagem. Esses achados evidenciam a necessidade de realização de pesquisas sobre manejo da dor pediátrica e os fatores que o influenciam.<br>Toda cirugía implica en lesión de tejidos, manipulación de estructuras y órganos, siendo el dolor una consecuencia de ese proceso, que puede ser minimizada. El presente estudio tiene como objetivo caracterizar, retrospectivamente, el proceso del manejo del dolor pos operatorio a partir de los registros contenidos en 300 prontuarios de 280 niños de 0 a 14 años sometidos a cirugía el año 2004 en tres hospitales de Londrina, PR, Brasil. El estudio indicó la existencia de pocos registros realizado por enfermeras, y la mayoría fue realizada por auxiliares o técnicos de enfermería. Los resultados evidencian la necesidad de la realización de pesquisas sobre el manejo del dolor pediátrico y los factores que lo influencian.<br>All surgical procedures involve tissue lesions, manipulation of structures and organs, causing pain which can be minimized during the process. The objective of this study is to characterize, retrospectively, the process of managing post-operative pain based on 300 medical records of 280 childre, who underwent surgery in 2004, in 3 hospitals located in Londrina, PR, Brazil. The study revealed that only a few nurses document post-operative pain, and that the majority of the records were made by nursing aides or technicians. The results have shown the need for research on pediatric pain management and the factors affecting them